In chemical vapor deposition (CVD) processes, such as silicon epitaxial growth processes, uniformity in the thickness of a deposited film on a substrate is dependent on, among other factors, uniformity in the flow distribution of gases within the process chamber. As the requirements for uniformity in film thickness become more stringent, the desire for more uniform flow rate distribution of gases in the process chamber increases.
Various attempts have been made to improve uniformity in gas flow distribution within CVD reactors, such as modifying the shape, size, or arrangement of static components (e.g., liners or baffle plates) within the CVD reactor. While such modifications may provide some improvements in gas flow distribution, known attempts to improve gas flow distribution generally have not provided a satisfactory ability to easily tune the gas flow distribution within the processing chamber.
Some known CVD reactors include multiple gas flow controllers that provide independent control of the gas flow rate through gas injection passages or channels. However, the construction of such known CVD reactors typically requires that the gas flow controllers be positioned relatively remote from the processing chamber. Consequently, there is a significant length of conduit or piping between the gas flow controllers and the inlet of the processing chamber, which reduces the precision with which gas flow rates can be controlled.
Accordingly, a need exists for a substrate processing system that improves the uniformity of gas flow distribution within the processing chamber and provides enhanced control over the gas flow rate of gases flowing into the processing chamber.
This Background section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.